The present invention relates generally to piston driven engines or machines and, more particularly, to an apparatus for increasing the mechanical efficiency of such engines or machines.
Improving the efficiencies and capacities of internal combustion engines and motor-driven piston operating machines, such as compressors, has been the object of numerous design innovations. Many of these innovations have related to the materials of construction, forms of lubrication, and integrity of the piston and cylinder arrangement.
There are known in the art means for providing variable stroke and variable compression in internal combustion engines. There are also constructions that enable specific combinations of piston stroke and piston position to be varied within a single machine. There is also known a lever arrangement whereby the speed of the piston strokes and the relative piston position are varied for purposes of maximizing efficiency. In a conventional reciprocating internal combustion engine, a piston drives the crankshaft through a connecting rod during the power stroke and the kinetic energy of the crankshaft and flywheel drives the piston in the compression stroke. With a crank and connecting rod of fixed length where the rotation is around the crankshaft, however, mechanical inefficiency is inevitable.
While most of the prior art devices have sought to improve the performance of the internal combustion engine, none have sought to improve the mechanical efficiencies of conventional piston, connecting rod, and crankshaft configurations typical in motor-driven compressors or reciprocating internal combustion engines.
The present invention is directed to an apparatus and method for increasing the mechanical efficiency of an internal combustion engine or other piston-driven machine of the type having a block that houses at least one piston, a piston connecting rod, and a crankshaft having at least one crank and at least one crankpin. Thus, the present invention maximizes the force that is doing the work in the operation of the machine. A further object of the present invention is to provide an apparatus and method for similarly increasing the mechanical efficiency of a piston-operating device such as a compressor.
Accordingly, one aspect of the present invention includes a lever and sliding bearing block combination that varies the relative position of the crankpin and connecting rod with respect to a fulcrum point to maximize the force delivered during each stroke of the piston. A lever is pivotally connected to an inner wall or extension of the block housing so that its range of movement is in a vertical plane that is substantially perpendicular to the center of the crankshaft. The pivotal connection becomes the fulcrum point for the engine. The lever is so formed to pivotally connect to the piston connecting rod at a point on its upper surface between the fulcrum point and the free end of the lever. A bearing block is slidably engaged to the lever along flanges extending outwardly from the bottom of the lever and formed substantially along the entire length of the lever as the engine or compressor operates. Thus, the bearing block is free to slide between the fulcrum point and the free end of the lever. Below the lever, a circular aperture is formed through the bearing block for pivotal connection with the crankpin of the crank.
When the piston connecting rod and crankpin of the internal combustion engine are connected to the lever and bearing block respectively, and the engine is placed in operation, the apparatus moves as the crankshaft and crank rotate to provide a mechanical advantage for the particular stroke of the piston. Specifically, on the explosive power (downward) stroke of the piston, the bearing block slides toward the fulcrum point of the lever to a position on the lever between the fulcrum point of the lever and the connecting rod connection on the lever to create a mechanical advantage for the piston; i.e., the moment (distance times force) of the piston exceeds the moment of the crankpin. Conversely, on the compression (upward) stroke of the piston, the bearing block slides to position the crankpin so that the crankpin is further from the fulcrum point than the connecting rod connection point on the lever, thus creating a mechanical advantage for the crankpin on the crankshaft.
The lever and sliding bearing block arrangement described above may be utilized on any conventional piston-operated machine, including, for example, motor-driven compressors. The construction of the lever and the way in which the device works is similar to the internal combustion engine. Specifically, the compression stroke of a compressor, such as a motor-driven compressor, is similar to the compression stroke of the internal combustion engine. That is, on the compression stroke of the compressor, the block slides to position the crankpin outward from the connecting rod connection on the lever to create a mechanical advantage for the crankshaft.
These and other aspects of the present invention will become apparent to those skilled in the art after a reading of the following description of the preferred embodiment when considered with the drawings.